Does conventional wisdom make economic sense? In many cases, it doesn't. This blog will question the economic efficiency and market viability of popular "solutions" to today's problems. Copyright 2011.

Monday, October 5, 2009

A More Efficient Hybrid?

Will the flywheel overtake the battery in the hybrid of tomorrow? Quite possibly!

If you have ever ridden a bicycle or watched a potter's wheel, you have seen a flywheel in action. When you pedal a bike, the wheels continue to spin even when you are not pedaling because the pedal energy has been stored and then released through the wheel.

Although flywheels have been known since ancient time, only now has their automotive potential become apparent.

In an article by Gizmag.com, Williams Formula 1 (F1) racing was looking for a solution to capture, store and use brake force energy (Kinetic Energy Recovery System KERS). While they had considered the typical battery solution, but found that a flywheel was lighter and more efficient. Were that the whole story, it would be great, but wait, there's more!

Williams created a separate company, Torotrak, to apply the flywheel KERS system to automobiles and found, surprisingly, that buses behave in a manner similar to F1 race cars. The similarity is found in the stop-start nature of buses and time between energy capture and release in F1 cars.

Here is a video explaining the flywheel's use in F1 racing.

What makes this concept economically efficient, and could possibly spell the end to the battery hybrid is that it can be retrofitted to existing transmissions and is more efficient. From the article:

“Our solution offers a much shorter pay back time on investment and does not reduce the number of passengers that can be carried,” explains Chris Brockbank of Torotrak. “It is also a fundamentally more efficient approach as energy remains in the mechanical state; with electrical regeneration there is an efficiency loss at each state change from mechanical to electrical to chemical and back again.”

Consider the economic benefits of a flywheel system versus a chemical battery. The flywheel is lighter, generally made of recyclable materials, and uses less hazardous materials than batteries. Additionally, they can be easily (relatively speaking) retrofitted onto existing transmissions. Finally, there are fewer components. Although I am huge fan of the hydraulic hybrid, the need for a direct drive transmission is slowing its development. However, if the flywheel technology proves itself, the need for hydraulic hybrids may no longer exist.

In the examination of hybrids, like any other capital investment, one has to consider if the money spent will provide larger returns. When considering a technology that can possibly deliver a 30% improvement in fuel economy and can reasonably be retrofitted to existing automobiles, it may make sense. I look forward to seeing the results of the continued studies and will report back with any updates.